With the rapid development of the Long Term Evolution (LTE) system, the 3rd Generation Partnership Project (3GPP) gradually develops research works on Long Term Evolution-Advanced (LTE-Advanced; LTE-A) related technologies. Compared with the LTE system, the LTE-Advanced system has a very large enhancement in terms of key technologies, and has successively introduced the Carrier Aggregation (CA), Relay, Coordinated Multiple Points (COMP), enhanced multi-antenna, uplink multi-antenna, etc.
In terms of system bandwidth, the LTE-A needs to support higher uplink and downlink transmission rates, the downlink needs to support a data transmission rate of 1 Gbps, and requirements are meet only when the bandwidth reaches to 100 MHz. In addition, the LTE-Advanced needs to be compatible with the LTE. Therefore, carrier aggregation is proposed in the LTE-Advanced. The carrier aggregation may be aggregation in continuous carriers, or may also be aggregation in non-continuous carriers.
Under the carrier aggregation, the number of component carriers designed by the LTE-A is 5 at most. Thus, for one UE, there may be a large number of bits of the response information fed back in the uplink control channel (including Acknowledgement (ACK), Negative Acknowledgement (NACK), and Discontinuous Transmission (DTX) of the base station). Then in a condition that the power of a User Equipment (UE) is limited, the UE may not transmit enough ACK/NACK information. The current LTE-Advanced system provides an ACK feedback mode of ACK/NACK for a single carrier and dual carriers, but as to an ACK/NACK feedback mode for more than two carriers, there is no solution in the related art.